In order to route signaling system 7 (SS7) messages, network elements within an SS7 network must be configured with a routable network identity or address (e.g., a point code address) and routing or path information associated with other network elements within the network. One aspect of message routing in an SS7 network that is of particular interest with respect to the subject matter described herein involves the load sharing of signaling messages among multiple network elements when signaling messages are sent route-on-point-code-subsystem-number. In conventional SS7 networks, the ability to load-share signaling messages between different groups of network elements is reserved for global-title-routed messages that are destined for mated network elements hosting mated subsystems. One type of signaling messages sent to network elements hosting mated application subsystems includes signaling connection control part (SCCP) messages. In one routing scenario, a signal transfer point (STP) may load share received messages between network elements that are assigned a particular subsystem. This allows stateless and stateful applications to process traffic between two or more mated nodes in the most efficient and reliable manner in the SS7 network. Typically, configuration of a mated subsystem table and global title translation (GTT) operations are required to facilitate this load sharing relationship between an STP and, for example, a service control point (SCP), or any other network element that hosts an application for which load sharing is desired.
One problem associated with the above-described load sharing techniques is illustrated in FIG. 1. In FIG. 1, a first network 100 includes a service switching point 102 and a signal transfer point 104. A second network 106 includes a signal transfer point 106 and service control points 108 and 110. When originating SSP 102 attempts to send a message to one of service control points 108 and 110 in network 106, originating service switching point 102 sends the message route-on-global-title to STP 104. STP 104 performs a global title translation, changes the routing indicator to route-on-point-code-subsystem-number (route-on-PC-SSN) and forwards the message to network 106. STP 107 and network 106 receives the message and routes the message based on point code and SSN to the appropriate SCP.
Because network 106 receives the message with the routing indicator marked route-on-point-code-SSN, there is no ability in network 106 to load share such messages among destinations, such as SCP 108 and SCP 110 when messages are sent route-on-PC-SSN. The inability to load share messages sent route-on-PC-SSN can be a significant disadvantage for terminating network operators because the ability of these operators to deploy identically provisioned nodes and load share messages between these nodes is limited.
In light of the inability to perform load sharing based on messages that are sent route-on-PC-SSN, there exists a need for improved methods and systems for load sharing signaling messages that are sent route-on-PC-SSN.